Decision-making, in the interview

Reversible vs irreversible decisions: one-way and two-way doors

Some decisions can be undone cheaply and some cannot. Jeff Bezos called them two-way and one-way doors: walk through a two-way door fast, because you can come back; slow down only for the one-way doors. In an interview, it turns a vague launch question into a clear call.

How does Reversible vs irreversible work?

Ask what it would cost to undo the decision, in money, time and trust.
If undoing is cheap, decide quickly with the information you have.
If it is expensive, slow down, gather evidence and involve more people.
Look for a way to turn a one-way door into a two-way door: a pilot, a phased rollout, a parallel run.

When does Reversible vs irreversible fit an interview question?

Use it whenever a question asks whether to launch now or wait, migrate or stay, commit or test. It is also the quickest way to show seniority: you spend time on the decisions that deserve it and move fast on the rest.

What does a strong answer with Reversible vs irreversible sound like?

Question: ship a release that is 90% bug-free in time for a holiday, or wait two weeks and miss it?

"It depends whether the remaining bugs can be undone. If they are cosmetic, shipping is a two-way door: we launch, catch the holiday and patch next week. If they touch checkout, a broken purchase over the holiday cannot be undone, in revenue or in trust, so that is a one-way door and I would wait. So my first question is where the bugs sit."

Common mistakes

Treating every choice as irreversible, which makes you sound slow.
Forgetting reputational cost: some changes are easy to roll back technically and hard to roll back with customers.
Stopping at the label instead of proposing a way to make the choice reversible.

Where does Reversible vs irreversible come from?

Jeff Bezos set it out in his 2015 letter to Amazon shareholders, as Type 1 decisions (irreversible, one-way doors, to be made slowly and carefully) and Type 2 decisions (reversible, two-way doors, to be made quickly by small groups). His warning was that large organizations tend to treat every decision as Type 1, and slow down as a result.

Practice with this framework

These problems from the free GCA practice set are best answered with Reversible vs irreversible. Pick the framework that fits each one, then read the worked answer.

3 questions, one at a time

Pick a pace. The timer stops when you check an answer, and the worked method opens straight away. Nothing is saved or sent anywhere.

Pace

Interview pace4 min per question, like the real roundSprint90 seconds per questionNo timerTake as long as you need

Keys: 1 to 4 pick an option, Enter checks and moves on.

One question, two answers

A weak answer, why it scores low, and the strong one. Under a minute each.

Migrate now or later?
Ship buggy for the holiday?

Reversible vs irreversible: FAQ

What is a one-way door decision?

A decision that is expensive or impossible to reverse, such as a major acquisition, a public commitment or a data migration with no way back. Bezos argued these deserve slow, careful deliberation, and that most decisions are not like this.

What is a two-way door decision?

A decision you can reverse cheaply if it turns out wrong, such as a pricing test or a feature behind a flag. These should be made fast, by a small group, with incomplete information.